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Cutting Foam Board

I purchased a 4' x 8' sheet of 2" thick Dow Corning Foam Board. What is the best way to cut this foam to get a nice edge? I am going to place this under the telescoping cover and above the inner cover on each of my hives.

Re: Cutting Foam Board

Because of the thickness its hard to get a straight square cut doing it with a long sharp knife like I do, but I don't see why you couldn't cut it on a table saw to get a better cut, or maybe a hand held jigsaw or circular saw. John

Re: Cutting Foam Board

The telescoping covers are the Mann Lake units. Probably about a 2" edge. I am going to place the insulation on the inner cover, then wrap the hive with 15 lb. felt/tar paper and fold it over the top of the foam. Then I will place the telescoping cover over that.

Re: Cutting Foam Board

Caution advised! You really need to control both pieces and preferable use a splitter. I had a chunk suck onto the blade of a table saw and pieces shattered and flew all over. You would not think the blade could get hold of it so!

Re: Cutting Foam Board

I cut some a week or two ago with a cheap handsaw from Home Depot. It was a lot easier than what I tried last year with a big knife. Also I noticed that the foam was scored at 16 and 32 inches in the long direction which made things even easier.http://s1110.photobucket.com/albums/...9-02141818.jpg

Re: Cutting Foam Board

We cut A LOT of this type of insulation when we built our house.
1. Use a long metal straight edge and a carpet knife with a SHARP/NEW blade.
2. Score the insulation as deeply as you can.
3. Place your sheet of insulation so your weight is on the main part of the sheet.
4. Let the part you want to remove hang over the edge of something - a saw horse, a table edge, etc.
5. Use a 2x4 to put pressure on the edge you want to remove until it breaks along the score.
Ta dah!

PS - We didn't have luck with a table saw or a circular saw - too dangerous, too.

Re: Cutting Foam Board

Utility knife or a carpet knife will work as described but it is a broken edge. This edge could be squared off by using a sanding block with coarse sandpaper. This is a bit messy.
As mentioned before a hot wire does make the best cut because it seals the edge. Getting the current in the wire and the wire feet rate takes a little practice to get the best cut.

When I was building cardboard airplanes I cut a lot of this foam for the ribs of the wings and actually built a pentagraph for the application. I was lucky enough to get my hands on some nitenel wire for the cutting blade which is an exotic metal that worked perfect.

Re: Cutting Foam Board

Most online RC hobby supply places will have it. Inconel is commonly used but you probably could get away with stainless steel as you would not need a long length exposed. I have cut wing cores for RC planes as Acebird mentions and was cutting 30 inches deep so the inconel can be stretched tighter in that case. The wire needs to be somewhat shy of visibly red so you have to play with resistances and power supply depending on your wire size.

I have cut lots of foam on the table saw and sure got a surprise when I got violent results. Thanks Blueribboncookies. I will still cut it on the table saw but not without a long splitter to be certain neither the sheet or the off cut can move sideways against the side of the blade.